Glaciers

I. Origin of Glaciers

A. Definition

1. Originates on land

I. Origin of Glaciers

A. Definition

1. Originates on land

2. Forms from the accumulation, compaction, and recrystallization of snow

I. Origin of Glaciers

A. Definition

1. Originates on land

2. Forms from the accumulation, compaction, and recrystallization of snow

3. Survives year-to-year

I. Origin of Glaciers

A. Definition

1. Originates on land

2. Forms from the accumulation, compaction, and recrystallization of snow

3. Survives year-to-year

4. Moves under its own weight

I. Origin of Glaciers

B. Elevation required18,000 ft. sea levelsea level 10,000 ft.

I. Origin of GlaciersC. Mechanism of Formation

I. Origin of Glaciers

D. Behavior of Flow

D. Behavior of Flow

1. Plastic Flow

D. Behavior of Flow

2. Basal Sliding (Slip)

D. Behavior of Flow

3. Zone of Fracture

crevasses

D. Behavior of Flow

3. Zone of Fracture

II. Types of Glaciers

A. Alpine Glaciers

II. Types of Glaciers

B. Continental Glaciers

III. Glacial Movement

Zone of accumulation

III. Glacial Movement

Zone of ablation

III. Glacial Movement

• Accumulation vs. ablation determines movement

III. Glacial Movement

• Accumulation vs. ablation determines movement

IV. Glacial Erosion

A. Processes for erosion

IV. Glacial Erosion

Glacial Striations

IV. Glacial Erosion

Glacial Polish

IV. Glacial Erosion

3) Bulldozing –

V. Erosional Landforms

V. Erosional Landforms

V. Erosional Landforms

A) Cirques –

A) Cirques……and Tarns

V. Erosional Landforms

2) Arete

V. Erosional Landforms

3) Horn –

V. Erosional Landforms

4) U-shaped valley

V. Erosional Landforms

5) Hanging valley

5) Hanging valley

V. Erosional Landforms

6) Fjords –

6) Fjords –

VI. Depositional Landforms

A) Moraines

VI. Depositional Landforms

A) Moraines

VI. Depositional Landforms

Lateral and Medial Moraines

VI. Depositional Landforms

Lateral Moraine –

Lateral Moraine

VI. Depositional Landforms

D) Medial Moraine –

Medial Moraine

A) Moraines

VI. Depositional LandformsGround and Terminal Moraines

VI. Depositional Landforms

Terminal moraine –

B) Drumlin –

B) Drumlin –

B) Drumlin –

C) Kettles

C) Kettles

D) Eskers

D) Eskers

VI. Depositional Landforms

E ) Outwash plain –

VII.Ice Ages

• Global cooling may produce glaciers

The Pleistocene Ice Age

• Four major glacial advances over past 1.8 million years

• Area covered?• Results?

The Pleistocene Ice Age

• Global sea level drop

The Pleistocene Ice Age

• Land bridges